Ge Est QS4 - Notification Appliance Circuit Wire Length Calculation

System calculations
A.2 QS4 Technical Reference Manual
Notification appliance circuit maximum wire length calculation
Use this worksheet to determine the maximum wire length of a notification appliance circuit. Fill in one
worksheet for each NAC connected to the panel.
Maximum signal loss allowed
1
1.5 V
×
1000
1500
Wire resistance per 1000 ft/pair
2
÷Ω
Total operating current required
3
÷
A
Maximum wire length ft
Notes
1. For worst case estimates, assume a 1.5 V line loss and all appliances are clustered at the
end of the circuit.
2. Use 3.5 for 12 AWG and 2.5 mm
2
wire, 5.2 for 14 AWG and 1.5 mm
2
wire, 8.0 for 16 AWG
and 1.0 mm
2
wire, and 13.0 for 18 AWG and 0.75 mm
2
wire.
3. Use the filtered 20 Vdc Average Operating Current ratings found on the installation or
catalog sheet of each device.
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